帕金森病患者视觉整体与局部认知功能研究

视觉形象经常被分为结构上的层级图形 ,脑对层级图形的视觉认知加工机制近年来得到细致的研究。韩世辉等发现正常人图形加工为整体优势 ,帕金森病 (ＰＤ)患者的视觉整体与局部的认知功能状况尚未见报道。我们对ＰＤ患者进行研究 ,以了解ＰＤ患者视觉整体与局部认知功能状况。资料和方法 :选门诊ＰＤ患者 30例及正常对照 30名 (ＮＣ组 ) ,利用改良Ｗｅｂｓｔｅｒ评分、Ｈｏｅｈｎ Ｙａｈｒ分级判断ＰＤ患者运动障碍程度及疾病分期 ;利用中国科技大学研究生院设计的视觉整体与局部认知功能检查软件对患者进行检查。刺激图是由小箭头组成的大箭…     

帕金森病患者视觉整体与局部认知功能研究

目的 探讨帕金森病(PD)患者视觉整体与局部认知功能。方法 利用中国科技大学研究生院认知实验室设计的整体与局部认知功能检查软件对30例PD患者和31例对照进行检查。结果 PD患者的反应时间(RT)较对照组无显著性差异(P>0.05)。进一步研究发现左侧肢体起病PD患者RT较对照组延长,右侧起病PD患者RT较对照组缩短,但除左侧起病PD患者整体(大小箭头方向一致)情况外,均无显著性差异。将左侧和右侧起病的PD患者进行对比发现,左侧起病患者各项RT(除局部大小箭头方向不一致情况外)均较右侧起病患者显著延长(P<0.05)。结论右侧基底节参与了视觉整体与局部的认知加工,左侧基底节可能对右侧基底节有抑制性调节作用。     

1例顶叶萎缩患者的神经心理学研究

双侧顶叶局限性进行性萎缩非常少见[1],我们发现1例,报道如下。1资料1.1一般资料:患者,女,67岁,右利手,文化程度大专,退休前是中学老师,因反应迟钝、主动语言减少2年于2005年11月就诊本院神经内科,头颅MR显示:双侧顶叶萎缩(图1)。大脑SPECT检查呈现顶叶局部脑血流量降低。MRA没     

正常人的视觉事件相关电位研究

本文利用三种视觉符号编排的刺激序列，记录了９５名正常人的视觉ＥＲＰ，报道了Ｆｚ、Ｐｚ点Ｎ２、Ｐ３波幅和潜伏期的正常值及Ｎ２、Ｐ３的影响因素。结果表明：该刺激序列可引出清晰、稳定的ＥＲＰ波形；Ｐ３波幅与任务和部位有关，靶Ｐ３波幅大于非靶Ｐ３，靶Ｐ３于Ｐｚ点波幅大于Ｆｚ，非靶Ｐ３在Ｆｚ、Ｐｚ点间波幅无明显差异；Ｎ２波幅与任务无关，靶与非靶之间Ｎ２波幅地无差异，而与部位有关，Ｆｚ点波大于Ｐｚ点；Ｎ２、Ｐ     

首次发病未服药精神分裂症患者立体视觉与认知功能的相关性研究

目的:研究首次发病未服药精神分裂症患者的立体视觉及其与认知功能的关系。方法:本研究起止时间为2019年1月至2020年9月;共招募146例首次发病未服药精神分裂症患者（首发精分组）、124例慢性期精神分裂症患者（慢性精分组）和101名健康对照者（对照组）。采用Titmus方法检测立体视觉,阳性与阴性症状量表评定患者临床...     

多发性硬化患者认知电位及视觉诱发电位的相关研究

目的:探讨多发性硬化(MS)患者事件相关电位(ERP)和视觉诱发电位(VEP)的变化.方法:对40例复发缓解型MS患者和40例健康人的ERP和VEP进行分析对比.结果:复发缓解型MS患者ERP的N2、P3波的潜伏期较对照组延长(P<0.05),VEP的P100、N145波的潜伏期较对照组延长(P<0.05).结论:ER...     

脑小血管病认知功能障碍与脑电的相关性研究

目的 分析和探讨脑小血管病认知功能障碍与脑电的相关性.方法 以2017年9月～2019年9月为时间基准,在我院所有脑小血管病认知功能障碍患者当中,随机收集60例作为本次研究的对象,将其设定为观察组,同期选取60名健康人群,作为对照组.对两组人群均进行脑电图检测,对比两组脑电图检测结果以及精神状态量表评分和蒙特利尔认知评...     

癫痫病人的认知功能与BRP的研究

报告６５名健康人，苯妥英钠，丙戊酸钠抗癫痫治疗患者（癫痫Ａ组）５４名，得理多治疗癫痫患者（癫痫Ｂ组）４２例的认知功能量表检测和ＥＲＰ检测结果，提示癫痫病人的认知功能有损害，Ｂ组认知功能受损轻于Ａ组，ＥＲＰ检测亦示癫痫患者认知功能受损。     

The role of parietal cortex in overimitation: a study with fNIRS

Previous studies have shown right parietal activation in response to observing irrational actions. Behavioral studies show that people sometimes imitate irrational actions, a phenomenon called overimitation. However, limitations on movement in functional magnetic resonance imaging (fMRI) mean that the neural basis of overimitation has not been studied. To address this, our study employed a less restrictive neuroimaging technique, functional near-infrared spectroscopy (fNIRS). Measurements were taken while participants observed either rational or irrational movements before performing movements on a computerized puzzle task. Observing irrational actions produced greater activation in right anterior inferior parietal lobule (aIPL), replicating results from the fMRI literature. This is a proof of principle that fNIRS can be used as an alternative to fMRI in social cognition experiments, and that parietal cortex has a core role in responding to irrational actions.     

The role of the posterior parietal lobe in prism adaptation: Failure to adapt to optical prisms in a patient with bilateral damage to posterior parietal cortex

We studied a patient (J.J.) with bilateral damage to those regions of the posterior parietal cortex (PPC) thought to be involved in prism adaptation. We demonstrated, for the first time in a parietal patient, that J.J. was unable to adapt to the visual perturbation induced by the optical prisms with either hand within four times the number of trials required by healthy adult subjects. We offer a novel account for the role of the PPC in prism adaptation: that the reach direction to the veridical target location specified in extrinsic limb-based coordinates must be de-coupled from the gaze direction to the perceived target location specified by intrinsic oculocentric coordinates in order to produce spatially accurate movements. This spatial discrepancy between gaze direction and reach direction may provide the necessary training signal required by the cerebellum to update the current internal model used to maintain spatial congruency between visual and proprioceptive maps of peripersonal space. The hypothesis is discussed in relation to recent disconnectionist accounts of optic ataxia.     

Emotion unfolded by motion: a role for parietal lobe in decoding dynamic facial expressions

Facial expressions convey important emotional and social information and are frequently applied in investigations of human affective processing. Dynamic faces may provide higher ecological validity to examine perceptual and cognitive processing of facial expressions. Higher order processing of emotional faces was addressed by varying the task and virtual face models systematically. Blood oxygenation level-dependent activation was assessed using functional magnetic resonance imaging in 20 healthy volunteers while viewing and evaluating either emotion or gender intensity of dynamic face stimuli. A general linear model analysis revealed that high valence activated a network of motion-responsive areas, indicating that visual motion areas support perceptual coding for the motion-based intensity of facial expressions. The comparison of emotion with gender discrimination task revealed increased activation of inferior parietal lobule, which highlights the involvement of parietal areas in processing of high level features of faces. Dynamic emotional stimuli may help to emphasize functions of the hypothesized ‘extended’ over the ‘core’ system for face processing.     

The role of the posterior parietal cortex in drawing by copying

Impaired ability to draw visually presented figures by copying represents one major manifestation of constructional apraxia (CA). Previous clinical studies have indicated that CA is caused by lesions in the posterior parietal cortex (PPC), but the functional roles of the PPC remain unclear. A spared ability to trace with an impaired ability to copy indicates that deficits lie not in low-level visuomotor processing, but rather in a coordinate transformation involving production of an egocentric representation of model trajectory in the drawing space, which is spatially separated from the model space. To test the hypothesis that the PPC plays a role in coordinate transformation, we compared brain activities for drawing by copying and tracing using functional magnetic resonance imaging (fMRI). Healthy participants traced over the visually presented model or copied the model on a separate space. To avoid potential confounders of differences in behavioral performances as well as eye movements, a memory-guided condition was introduced, resulting in four drawing conditions; tracing over or copying a model at different locations (tracing and copying), with or without an on-screen model (visual and memory guidance). As hypothesized, the intraparietal sulcus (IPS) bilaterally in the PPC showed significantly greater activations in copying than in tracing, under both visual and memory guidance, with a distinct activation pattern involving the premotor and mesial motor regions. This study indicates a role of the PPC in coordinate transformation for drawing by copying, which may be important for the copying deficit observed in CA.     

Egocentric memory impaired and allocentric memory intact as assessed by virtual reality in subjects with unilateral parietal cortex lesions

Present evidence suggests that medial temporal cortices subserve allocentric representation and memory, whereas egocentric representation and memory mainly depends on inferior and superior parietal cortices. Virtual reality environments have a major advantage for the assessment of spatial navigation and memory formation, as computer-simulated first-person environments can simulate navigation in a large-scale space. However, virtual reality studies on allocentric memory in subjects with cortical lesions are rare, and studies on egocentric memory are lacking. Twenty-four subjects with unilateral parietal cortex lesions due to infarction or intracerebral haemorrhage (14 left-sided, 10 right-sided) were compared with 36 healthy matched control subjects on two virtual reality tasks affording to learn a virtual park (allocentric memory) and a virtual maze (egocentric memory). Subjects further received a comprehensive clinical and neuropsychological investigation, and MRI lesion assessment using T₁, T₂ and FLAIR sequences as well as 3D MRI volumetry at the time of the assessment. Results indicate that left- and right-sided lesioned subjects did not differ on task performance. Compared with control subjects, subjects with parietal cortex lesions were strongly impaired learning the virtual maze. On the other hand, performance of subjects with parietal cortex lesions on the virtual park was entirely normal. Volumes of the right-sided precuneus of lesioned subjects were significantly related to performance on the virtual maze, indicating better performance of subjects with larger volumes. It is concluded that parietal cortices support egocentric navigation and imagination during spatial learning in large-scale environments.     

Visual function in children with neonatal brain lesions

Book Reviewed in this articles.
Neurological Assessment in the First Two Years of Life Edited by Giovanni Cioni and Eugenio Mercuri     

The effect of oppositional parietal transcranial direct current stimulation on lateralized brain functions

Cognitive functions such as numerical processing and spatial attention show varying degrees of lateralization. Transcranial direct current stimulation (tDCS) can be used to investigate how modulating cortical excitability affects performance of these tasks. This study investigated the effect of bi‐parietal tDCS on numerical processing, spatial and sustained attention. It was hypothesized that tDCS would have distinct effects on these tasks because of varying lateralization (numerical processing left, spatial attention right) and that these effects are partly mediated by modulation of sustained attention. A single‐blinded, crossover, sham‐controlled study was performed. Eighteen healthy right‐handed participants performed cognitive tasks during three sessions of oppositional parietal tDCS stimulation: sham; right anodal with left cathodal (RA/LC); and right cathodal with left anodal (RC/LA). Participants performed a number comparison task, a modified Posner task, a choice reaction task (CRT) and the rapid visual processing task (RVP). RA/LC tDCS impaired number comparison performance compared with sham, with slower responses to numerically close numbers pairs. RA/LC and RC/LA tDCS had distinct effects on CRT performance, specifically affecting vigilance level during the final block of the task. No effect of stimulation on the Posner task or RVP was found. It was demonstrated that oppositional parietal tDCS affected both numerical performance and vigilance level in a polarity‐dependent manner. The effect of tDCS on numerical processing may partly be due to attentional effects. The behavioural effects of tDCS were specifically observed under high task demands, demonstrating the consequences of an interaction between stimulation type and cognitive load.